Begin every vocal exercise with a good warm-up. Start by singing long tones. Move on to "hmm" exercises in which you start on a pitch that is comfortable and sing the vocal down a perfect fifth. Continue this exercise a half-step higher to the uppermost point of your comfortable range.
Sing along with the piano, starting at a note that is comfortable and easy to sing. Matching pitch with the piano, sing half-steps until you have reached the highest note that you can sing easily. If you can sing an A above the staff or higher, you might be a soprano since fully developed sopranos can easily sing over A. However, a mezzo can also sing above A, so this is only one aspect of a soprano singer.
Determine your passaggio, which is the transition between one register and the next, by listening carefully to where your voice quality changes. Sopranos will notice a distinct change in voice quality when singing an E on the top space of the staff to an F. If you are a mezzo, the change will appear lower in the voice around D or even C.
Record your voice and listen to it carefully. Mezzos have a rich, thick texture throughout, while sopranos have a thinner, more narrowly defined texture and penetrating voice. Additionally, sopranos have a bright and ringing texture, and sing light and agile passages with ease. The strongest part of a soprano range is the high register above F, while the strongest part of a mezzo is the middle range.